Novel methods for real-time observation of molecularly thin lubricant films by ellipsometric microscopy

New methods for real-time observation of molecularly thin lubricant on magnetic disks are discussed. Here, two types of ellipsometric microscopes are considered. One is vertical-objective setup with off-axis Kohler illumination type and another one is two-stage imaging type. Both can provide 0.1-μm-order lateral resolution and 0.1-nmorder thickness resolution at a high image capture speed. These methods are expected to be useful for clarifying the interaction between head and disks with an extremely small gap in high density hard disk drives.